Long-term subscribers feel motivated to have their subscription offer running for a longer period of time. A common practice that you can adopt here is sending them free products after a certain amount of time has passed (or some billing cycles).
Our Loyalty Feature can assist you in this endeavor. You can implement it within the subscription plan settings.
There is a dedicated option for FREE PRODUCTS offered within the subscription plans loyalty functionality.
After a specified number of billing cycles, this functionality can be used to offer free products (as gifts) to subscribers.